Răspuns:
Explicație pas cu pas:
a. a/b = 5/3 , 3a= 5b , a= 5b/3
a-b= 56
5b/3-b= 56
aduci la acelasi numitor (3)
5b-3b=168
2b=168 , b= 168/2= 84
a-b= 56 , a=56+84 = 140
b . a+b = 168 , a= 5b/3
5b/3 +b = 168
5b+3b = 504
8b=504 , b= 504/8 = 63
a+63= 168 , a= 168-63 = 105
c. 2a+5b=150
a= 5b/3
2·5b/3+5b = 150
10b+15b=150
25b=150 , b=150/25 = 6
2a+5·6 = 150
2a+30 = 150
2a=120 , a= 120/2 = 60
d. 4a+2b=260
4·5b/3 +2b = 260
20b +6b =260
26b=260 , b= 260/26 = 10
4a+2·10 =260
4a +20 = 260
4a = 260-20
4a = 240 , a= 240/4 = 60
